An example of an electronically controlled fuel injector is shown in U.S. Pat. No. 5,551,398 to Gibson et al. Fuel injection is controlled in this injector with a single solenoid that has the ability to move two separate armatures. A fuel spillage valve member is attached to a first armature, and a needle control valve member is attached to a second armature. When the spill valve member is in its open position, fuel pressure cannot build within the fuel injector. Upon closing the spill valve member, fuel is trapped within the injector and a plunger moves downward to pressurize fuel. The plunger is mechanically driven downward by a cam/rocker arm and tappet assembly. When fuel pressure builds within the injector and the needle control valve member is in its on position, fuel will commence to spray out of the nozzle outlet when the fuel pressure is above a valve opening pressure sufficient to overcome a needle check return spring. When fuel pressure is high and the needle control valve member is in its off position, high pressure fuel is directed to a closing hydraulic surface on one end of the needle check to close the same to provide an abrupt end to an injection event.
In this injector, the solenoid must necessarily be positioned deep within the injector body, and electricity to energize the solenoid must be brought from the outside of the injector body to the solenoid assembly. In this prior art injector, the solenoid assembly is glued into the injector body. Engineers are often seeking ways to improve the sealing of the injector body against leakage, especially where the electrical conductors penetrate the injector body. Furthermore, engineers are often looking for ways to improve solenoid assemblies and terminal assemblies in order to decrease complexity during production by making the terminal and solenoid assemblies as separate integral components with decreased part counts. In addition, by improving the mating between these sub assemblies and an injector body, the robustness and working life of an injector when fully assembled can be improved.
The present invention is directed to improving solenoid assemblies, terminal assemblies and fuel injectors that utilize both.